Metal mask for vapor deposition, and method for manufacturing metal mask for vapor deposition

Abstract

This metal mask for vapor deposition comprises a metal mask substrate for vapor deposition, the substrate comprising: a front surface which has a first opening that faces a vapor deposition source provided to a vapor deposition device; a back surface which is on the opposite side from the front surface and which has a second opening that is smaller than the first opening; and a through-hole which communicates the first opening and the second opening and has the shape of an inverted truncated spindle. The metal mask for vapor deposition further comprises an antifouling layer that contains a fluorine compound and is located on the front surface and an inner wall surface that demarcates the through-hole. A halogen-based compound that includes halogen atoms is not located on the back surface, the contact angle of water on a front surface of the antifouling layer is at least 90°, and the surface roughness Sa of the front surface of the metal mask substrate for vapor deposition is 10-80 nm inclusive.

Description

Technical Field

[0001] The present disclosure relates to a metal mask for vapor deposition and a method for manufacturing the metal mask for vapor deposition.

Background Art

[0002] In display devices of small devices typified by smartphones and head-mounted displays, and in organic EL displays attracting attention as future flexible displays, higher definition is required. Main methods for forming pixels of an organic EL display include a vapor deposition method and a coating method. Currently, mainly the vapor deposition method is adopted as a method for forming pixels of an organic EL display from the viewpoint of element characteristics. Therefore, it is common to form a light-emitting layer or the like included in a pixel by a vapor deposition method.

[0003] The metal mask for vapor deposition used in the vapor deposition process for forming pixels has through holes. In the vapor deposition process, organic molecules for forming a desired pixel pattern on a substrate pass through the through holes. The organic molecules are a light-emitting material sublimated from a vapor deposition source or the like. When patterning of pixels by vapor deposition, that is, formation of pixels, is repeated using the same metal mask for vapor deposition, organic molecules are deposited on the surface of the metal mask for vapor deposition facing the vapor deposition source, and clogging occurs due to deposition of organic molecules in the through holes, thereby causing patterning defects. Therefore, it is necessary to perform cleaning for removing organic molecules from the surface of the metal mask for vapor deposition and the pattern portion of the metal mask for vapor deposition, that is, the through holes.

[0004] On one hand, organic molecules fly in from various directions, i.e., multi-directionally, onto the evaporation metal mask, and these organic molecules adhere to the substrate for forming the pixel pattern. Therefore, in the through-holes included in the cross-section of the evaporation metal mask, when etching the evaporation metal mask substrate from only one side to form the through-holes, the angle formed between the surface facing the evaporation source and the back surface facing the substrate by the surface connecting them is required to be 45° or less. On the other hand, when etching the evaporation metal mask substrate from both the front and back surfaces to form the through-holes, the angle formed between the surface facing the evaporation source and the surface connecting the surface recess and the part where the surface recess is connected to the back surface recess by the surface connecting them is required to be 45° or less. Due to this design constraint, as the pixel density increases, i.e., with high definition, the thickness of the evaporation metal mask must be reduced.

[0005] However, as the evaporation metal mask becomes thinner, it is more likely to be deformed by cleaning. The evaporation metal mask is generally cleaned by ultrasonic cleaning. Since the evaporation metal mask is likely to be deformed by cleaning, treating the surface of the substrate forming the evaporation metal mask with an omniphobic substance such as a fluorine-containing substance has been considered (for example, refer to Patent Document 1). For the metal mask for printing plates, fluorine processing of the metal surface has been considered (for example, refer to Patent Document 2).

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0007] However, since halogen substances such as fluorine are suspected of affecting the light-emitting characteristics and reducing the light-emitting lifetime of the organic EL element, the transfer of halogen substances from the vapor deposition metal mask to the substrate has become a problem.

Means for Solving the Problem

[0008] The metal mask for vapor deposition for solving the above problems includes a front surface having a first opening facing a vapor deposition source provided in a vapor deposition apparatus, a back surface opposite to the front surface and having a second opening smaller than the first opening, and a through hole communicating with the first opening and the second opening, and includes a metal mask substrate for vapor deposition having the through hole with an inverted frustum shape. The metal mask for vapor deposition further includes an antifouling layer containing a fluorine compound on the front surface and the inner wall surface of the through hole. A halogen-based compound containing a halogen atom is not located on the back surface, the contact angle of the surface of the antifouling layer with respect to water is 90° or more, and the surface roughness Sa on the front surface of the metal mask substrate for vapor deposition is 10 nm or more and 80 nm or less.

[0009] The metal mask for vapor deposition for solving the above problems includes a front surface having a first opening facing a vapor deposition source provided in a vapor deposition apparatus, a back surface opposite to the front surface and having a second opening smaller than the first opening, and a through hole communicating with the first opening and the second opening, and includes a metal mask substrate for vapor deposition having a first hole portion including the first opening and having an inverted frustum shape, and a second hole portion including the second opening and having a frustum shape and smaller than the first hole portion. The metal mask for vapor deposition includes an antifouling layer containing a fluorine compound on the front surface and the inner wall surface defining the first hole portion, a halogen-based compound containing a halogen atom is not located on the back surface and the inner wall surface defining the second hole portion, the contact angle of the surface of the antifouling layer with respect to water is 90° or more, and the surface roughness Sa on the surface of the metal mask substrate for vapor deposition is 10 nm or more and 80 nm or less.

[0010] In the metal mask for vapor deposition, the material for forming the metal mask substrate for vapor deposition may be an iron-nickel alloy or an iron-nickel-cobalt alloy. In the metal mask for vapor deposition, the thickness of the metal mask substrate for vapor deposition may be 1 μm or more and 100 μm or less.

[0011] A method for manufacturing a metal mask for vapor deposition for solving the above problems includes preparing a metal mask substrate for vapor deposition having a front surface for forming a first opening facing a vapor deposition source provided in a vapor deposition apparatus and a back surface located on the opposite side of the front surface and for forming a second opening smaller than the first opening, forming a resin layer on the back surface, forming a through-hole having an inverted frustum shape by wet-etching the metal mask substrate for vapor deposition from the front surface, thereby forming the first opening on the front surface and forming the second opening on the front surface, forming an antifouling layer containing a fluorine compound on the front surface and an inner wall surface defining the through-hole, and chemically removing the resin layer from the metal mask substrate for vapor deposition by exposing the metal mask substrate for vapor deposition and the resin layer to an alkaline solution after forming the antifouling layer.

[0012] In the method for manufacturing the metal mask for vapor deposition, the resin layer may be made of polyimide. A method for manufacturing a metal mask for vapor deposition for solving the above problems includes preparing a metal mask substrate for vapor deposition having a front surface for forming a first opening facing a vapor deposition source provided in a vapor deposition apparatus and a back surface located on the side opposite to the front surface and for forming a second opening smaller than the first opening, providing a second hole portion having a truncated cone shape with the second opening on the back surface by wet etching, providing a resin layer on the back surface so as to cover the second opening, wet etching the metal mask substrate for vapor deposition from the front surface to form a first hole portion having an inverted truncated cone shape and the first opening, thereby forming a through hole by the second hole portion and the first hole portion, forming an antifouling layer containing a fluorine compound on the front surface and an inner wall surface defining the first hole portion, and chemically removing the resin layer from the metal mask substrate for vapor deposition by exposing the resin layer and the metal mask substrate for vapor deposition to an alkaline solution after forming the antifouling layer.

[0013] In the method for manufacturing the metal mask for vapor deposition, the resin layer may be made of a photosensitive resin. In the method for manufacturing the metal mask for vapor deposition, the resin layer may be made of polyimide.

[0014] A method for manufacturing a metal mask for vapor deposition to solve the above problems includes preparing a metal vapor deposition mask substrate having a front surface for forming a first opening facing a vapor deposition source provided in a vapor deposition apparatus, and a back surface located on the opposite side of the front surface and for forming a second opening smaller than the first opening; forming a resin layer on the back surface; wet-etching the vapor deposition mask substrate from the front surface to form a through-hole having an inverted frustum shape, thereby forming the first opening on the front surface and the second opening on the back surface; forming an antifouling layer containing a fluorine compound on the front surface and the inner wall surface defining the through-hole; after forming the antifouling layer, exposing the vapor deposition mask substrate and the resin layer to ultraviolet rays to reduce the adhesion of the resin layer to the vapor deposition mask substrate; and peeling off the resin layer with reduced adhesion from the vapor deposition mask substrate.

[0015] In the method for manufacturing the metal mask for vapor deposition, the resin layer may be made of an ultraviolet curable adhesive.

Advantages of the Invention

[0016] According to the present invention, the vapor deposition material deposited on the metal mask for vapor deposition can be easily removed, and deformation of the metal mask for vapor deposition due to ultrasonic cleaning can be suppressed.

Brief Description of the Drawings

[0017]

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[0018] Hereinafter, with reference to the drawings, a metal mask for vapor deposition and a method for manufacturing the metal mask for vapor deposition will be described. Here, the drawings are schematic, and the relationship between the thickness and the planar dimensions, the ratio of the thicknesses of the respective layers, etc. are different from the actual ones. Further, the embodiments shown below are examples of configurations for embodying the technical idea of the present invention, and the technical idea of the present invention does not specify the materials, shapes, and structures of the components, etc. as the following ones. The technical idea of the present disclosure can be variously modified within the technical scope defined by the claims described in the claims.

[0019] [Metal Mask for Vapor Deposition] As shown in FIG. 1, the mask device 10 includes a main frame 20 and a plurality of metal mask sheets 30 for vapor deposition. The main frame 20 has a frame shape that supports the plurality of metal mask sheets 30 for vapor deposition. The main frame 20 is attached to a vapor deposition apparatus for performing vapor deposition. The main frame 20 defines a main frame hole 21. A part of each metal mask sheet 30 for vapor deposition is located within the main frame hole 21.

[0020] The metal mask sheet 30 for vapor deposition includes a mask frame 31 and a metal mask 32 for vapor deposition. The mask frame 31 has a strip shape for supporting the metal mask 32 for vapor deposition. The mask frame 31 is attached to the main frame 20. The mask frame 31 has the same number of mask frame holes 33 as the number of metal masks 32 for vapor deposition. One mask frame hole 33 is a hole that penetrates substantially the entire range where one metal mask 32 for vapor deposition is located within the mask frame 31. The mask frame 31 has higher rigidity than the metal mask 32 for vapor deposition and has a frame shape surrounding the mask frame hole 33. In the mask frame 31, the portion partitioning the mask frame hole 33 is the inner edge portion 31E (see FIG. 4). The metal mask 32 for vapor deposition is fixed to the inner edge portion 31E by welding, adhesion, etc.

[0021] Referring to FIGS. 2 and 3, the metal mask 32 for vapor deposition will be described in more detail. Hereinafter, matters common to the metal mask 32 for vapor deposition shown in FIG. 2 and the metal mask 32 for vapor deposition shown in FIG. 3 will be described. Next, matters specific to each metal mask 32 for vapor deposition will be described.

[0022] As shown in FIGS. 2 and 3, the metal mask 32 for vapor deposition in the metal mask sheet 30 for vapor deposition includes a metal mask substrate 32S for vapor deposition and an antifouling layer 32AF. The metal mask 32 for vapor deposition includes a surface 32a of the metal mask substrate for vapor deposition (hereinafter referred to as surface 32a) and a back surface 32b of the metal mask substrate for vapor deposition which is also the surface opposite to the surface 32a (hereinafter referred to as back surface 32b). At least one of the surface 32a and the back surface 32b is a target surface for the resist layer to be located. The target surface is the surface on which the resist mask is formed in the process of forming the metal mask 32 for vapor deposition.

[0023] The metal mask substrate 32S for vapor deposition may be formed from a single metal sheet or may be formed from a multi-layer metal sheet. The metal mask substrate 32S for vapor deposition is made of metal. The material for forming the metal mask substrate 32S for vapor deposition may be, for example, an iron-nickel alloy or an iron-nickel-cobalt alloy. The iron-nickel alloy has iron and nickel as main components and contains, for example, 30% by mass or more of nickel and the balance of iron as a remainder. Among iron-nickel alloys, an alloy containing 36% by mass of nickel, that is, invar, is preferable as the material for forming the metal mask 32 for vapor deposition. In invar, the remainder with respect to 36% by mass of nickel may contain additives other than the main component iron. The additives are, for example, chromium, manganese, carbon, and cobalt. The additives contained in the iron-nickel alloy are at most 1% by mass or less.

[0024] In the iron-nickel-cobalt alloy, an alloy containing 32% by mass of nickel and 4% by mass or more and 5% by mass or less of cobalt, that is, super-invar, is preferable as the material for forming the metal mask substrate 32S for vapor deposition. In super-invar, the remainder with respect to 32% by mass of nickel and 4% by mass or more and 5% by mass or less of cobalt may contain additives other than the main component iron. The additives are, for example, chromium, manganese, and carbon. The additives contained in the iron-nickel-cobalt alloy are at most 0.5% by mass or less.

[0025] The thermal expansion coefficient of the iron-nickel-cobalt alloy is smaller than that of the iron-nickel alloy. The alloy forming the vapor deposition metal mask substrate 32S is preferably an iron-nickel alloy, and may also be an iron-nickel-cobalt alloy.

[0026] The surface 32a of the vapor deposition metal mask substrate 32S satisfies the following [Condition 1]. [Condition 1] The surface roughness Sa satisfies the following formula. 10 nm ≤ Sa ≤ 80 nm

[0027] The surface roughness Sa is a value measured by a method conforming to ISO 25178. When the surface roughness Sa is less than 10 nm, the deposits of the vapor deposition material can be removed by ultrasonic cleaning. However, during vapor deposition, the deposits on the metal mask are peeled off and spark at the vapor deposition source. Due to the spark, a problem occurs where the vapor deposition material cannot be uniformly vapor-deposited. That is, when the surface roughness Sa is 10 nm or more, the deposits of the vapor deposition material can be removed by ultrasonic cleaning. Further, when the surface roughness Sa is 10 nm or more, the deposits on the vapor deposition metal mask 32 during vapor deposition are peeled off, and then, the peeled deposits are prevented from sparking by falling onto the vapor deposition source.

[0028] When the surface roughness Sa exceeds 80 nm, even if the metal surface is fluorinated, due to the physical anchor effect between the metal surface and the deposits of the vapor deposition material, a problem occurs where the deposits of the vapor deposition material on the vapor deposition metal mask substrate cannot be removed by ultrasonic treatment. That is, when the surface roughness Sa is 80 nm or less, the anchor effect of the surface of the vapor deposition metal mask 32 on the deposits of the vapor deposition material is suppressed, and thereby, the deposits on the surface of the vapor deposition metal mask 32 subjected to the fluorination treatment can be removed by ultrasonic treatment.

[0029] The antifouling layer 32AF contains a fluorine compound. The antifouling layer 32AF has a surface on the side opposite to the surface in contact with the vapor deposition metal mask substrate 32S. The surface of the antifouling layer 32AF satisfies the following [Condition 2].

[0030] [Condition 2] The contact angle of the antifouling layer 32AF with respect to water on the surface is 90° or more.

[0031] Since the contact angle of the antifouling layer 32AF is 90° or more, the adhesion of the vapor deposition material to the antifouling layer 32AF becomes weak, and thus, the deposits on the antifouling layer 32AF can be removed by ultrasonic treatment.

[0032] As the material for forming the antifouling layer 32AF, a material containing a fluorine compound, which is insoluble in a solvent and has a property of easily removing attached slag, can be appropriately selected and used. For example, as the antifouling layer 32AF of the present invention, antifouling materials conventionally known in fields such as "antireflection film" and "water-repellent sheet" can be used.

[0033] As the manufacturing method of the vapor deposition metal mask substrate 32S, any one of (A) electrolysis, (B) rolling and polishing, (C) electrolysis and polishing, and (D) only rolling is used.

[0034] When the vapor deposition metal mask substrate 32S is an invar sheet, the thermal expansion coefficient of the vapor deposition metal mask substrate 32S is 1.2×10 -6 / °C or so. Further, if the vapor deposition metal mask substrate 32S is a super invar sheet, the thermal expansion coefficient of the vapor deposition metal mask substrate 32S is 0.5×10 -6 / °C or so. According to the vapor deposition metal mask substrate 32S having such a thermal expansion coefficient, the degree of thermal expansion in the vapor deposition metal mask 32 and the degree of thermal expansion in the glass substrate are matched. Therefore, in vapor deposition using the mask apparatus 10, it is preferable to use a glass substrate as an example of the vapor deposition target.

[0035] The vapor deposition metal mask substrate 32S includes a front surface 32a and a back surface 32b as described above. The front surface 32a is a surface for facing the vapor deposition source in the vapor deposition apparatus. The back surface 32b is a surface for contacting or approaching the vapor deposition target such as a glass substrate in the vapor deposition apparatus. Note that the back surface 32b is an example of a contact surface or an adjacent surface, and the front surface 32a is an example of a non-contact surface.

[0036] The thickness of the vapor deposition metal mask substrate 32S is 1 μm or more and 100 μm or less, preferably 1 μm or more and 40 μm or less. If the thickness of the vapor deposition metal mask substrate 32S is 40 μm or less, the depth of the holes formed in the vapor deposition metal mask substrate 32S can be 40 μm or less. When higher resolution is required for the vapor deposition metal mask 32, the thickness of the vapor deposition metal mask substrate 32S is, for example, 1 μm or more and 15 μm or less. Among these, if the thickness of the vapor deposition metal mask substrate 32S is 5 μm or less, the depth of the vapor deposition metal mask hole 32H (hereinafter, mask hole 32H), which is an example of the through hole formed in the vapor deposition metal mask substrate 32S, can be 5 μm or less. With such a thin vapor deposition metal mask substrate 32S, when viewing the vapor deposition target from the vapor deposition particles flying toward the vapor deposition metal mask 32, it is possible to reduce the portion hidden by the vapor deposition metal mask 32, that is, to suppress the shadow effect.

[0037] Note that if the thickness of the vapor deposition metal mask substrate 32S is 3 μm or more and 5 μm or less, the vapor deposition metal mask substrate 32S can have mask holes 32H that are a plurality of mask holes 32H spaced apart from each other in a plan view facing the front surface 32a and that can be used for manufacturing a high-resolution display device with a resolution of 700 ppi or more and 1000 ppi or less. Also, if the thickness of the vapor deposition metal mask substrate 32S is 10 μm or more and 15 μm or less, the vapor deposition metal mask substrate 32S can have mask holes 32H that are a plurality of mask holes 32H spaced apart from each other in a plan view facing the front surface 32a and that can be used for manufacturing a low-resolution display device with a resolution of 300 ppi or more and 400 ppi or less.

[0038] In the example shown in FIG. 2, the metal mask 32 for vapor deposition has a plurality of mask holes 32H penetrating through the metal mask substrate 32S for vapor deposition. The hole side surfaces partitioning the mask holes 32H have an inverted frustum shape protruding outwardly of the mask holes 32H in a cross section along the thickness direction of the metal mask substrate 32S for vapor deposition.

[0039] The front surface 32a includes a surface opening H1 which is an opening of the mask hole 32H. The back surface 32b includes a back surface opening H2 which is an opening of the mask hole 32H. The surface opening H1 is an example of the first opening, and the back surface opening H2 is an example of the second opening. In a plan view facing the front surface 32a, the size of the surface opening H1 is larger than that of the back surface opening H2. Each mask hole 32H is a passage through which the vapor deposition particles sublimated from the vapor deposition source pass. The vapor deposition particles sublimated from the vapor deposition source proceed in the mask hole 32H from the surface opening H1 toward the back surface opening H2. In the mask hole 32H, since the surface opening H1 is larger than the back surface opening H2, it is possible to suppress the shadow effect on the vapor deposition particles entering from the surface opening H1.

[0040] On the front surface 32a, each surface opening H1 is separated from the other surface openings H1. In other words, on the front surface 32a, each surface opening H1 is not continuous with the other surface openings H1. Therefore, in a plan view facing the front surface 32a, it is suppressed that the thickness of the portion located between the surface openings H1 in the metal mask 32 for vapor deposition becomes thinner than the thickness of the portion where no mask hole 32H is formed in the metal mask 32 for vapor deposition. Thereby, it is suppressed that the mechanical strength of the metal mask 32 for vapor deposition decreases. On the other hand, when one surface opening H1 is continuous with the other surface openings H1 on the front surface 32a, the thickness at the portion where the two surface openings H1 are continuous becomes thinner than the portion where no mask hole 32H is formed in the metal mask 32 for vapor deposition. As a result, the mechanical strength of the metal mask 32 for vapor deposition decreases as compared with the case where each surface opening H1 is separated from the other surface openings H1.

[0041] In addition, if the thickness of the metal mask 32 for vapor deposition is 3 μm or more and 5 μm or less, only by wet-etching the metal mask substrate 32S for vapor deposition from the surface 32a, a plurality of mask holes 32H capable of manufacturing the above-described high-resolution display device can be formed. Further, if the thickness of the metal mask 32 for vapor deposition is 10 μm or more and 15 μm or less, only by wet-etching the metal mask substrate 32S for vapor deposition from the surface 32a, a plurality of mask holes 32H capable of manufacturing the above-described low-resolution display device can be formed. Thus, in any case, it is not necessary to wet-etch the metal mask substrate 32S for vapor deposition from the back surface 32b.

[0042] The metal mask substrate 32S included in the metal mask 32 for vapor deposition shown in FIG. 2 satisfies the following [Condition 3]. [Condition 3] A halogen-based compound containing a halogen atom is not located on the back surface 32b.

[0043] In the metal mask 32 for vapor deposition shown in FIG. 2, the antifouling layer 32AF is located on the surface 32a and the inner wall surface defining the mask holes 32H which are through holes, but is not located on the back surface 32b. Therefore, a halogen-based compound containing a halogen atom is not located on the back surface 32b.

[0044] Note that the halogen atom may be at least one of a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. That is, the halogen-based compound may be a compound containing at least one of a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. The halogen-based compound may be a fluorine-based compound containing fluorine. The fluorine-based compound may be, for example, a material for forming the antifouling layer 32AF.

[0045] On the other hand, in order to form the metal mask 32 for vapor deposition used in the manufacture of display devices having each resolution using a thicker metal mask substrate 32S for vapor deposition, it is necessary to wet-etch the metal mask substrate 32S for vapor deposition from each of the surface 32a and the back surface 32b.

[0046] In this case, as shown in FIG. 3, the mask hole 32H includes a front surface recess 32LH and a back surface recess 32SH. The front surface recess 32LH is an example of the first hole portion, and the back surface recess 32SH is an example of the second hole portion. The front surface recess 32LH is an inverted frustum-shaped recess formed by wet-etching the vapor deposition metal mask substrate 32S from the front surface 32a. The back surface recess 32SH is a frustum-shaped recess formed by wet-etching the vapor deposition metal mask substrate 32S from the back surface 32b. The front surface recess 32LH is connected to the back surface recess 32SH at a position closer to the back surface opening H2 with respect to the central portion in the thickness direction of the vapor deposition metal mask 32. In the mask hole 32H, the portion where the front surface recess 32LH is connected to the back surface recess 32SH is the connection portion. That is, the mask hole 32H includes the front surface recess 32LH, the connection portion, and the back surface recess 32SH, whereby the mask hole 32H, which is a through hole, is formed.

[0047] The area of the mask hole 32H along the direction parallel to the front surface 32a is the smallest at the connection portion. In such a mask hole 32H, the distance between the back surface opening H2 and the connection portion is the step height SH. The larger the step height SH, the greater the above-described shadow effect.

[0048] Therefore, in the vapor deposition metal mask 32 shown in FIG. 3, from the viewpoint of suppressing the shadow effect, the step height SH is preferably 2 μm or less, more preferably 1 μm or less, and even more preferably 0.5 μm or less.

[0049] On the other hand, in the vapor deposition metal mask 32 shown in FIG. 2 described above, the step height SH is zero. In this case, the mask hole 32H, which is a through hole, is formed only by the front surface recess 32LH in the mask hole 32H shown in FIG. 2.

[0050] In FIG. 3, in a plan view facing the surface 32a, the plurality of mask holes 32H are spaced apart from each other. However, when wet etching is performed from the surface 32a, the adjacent surface recesses 32LH interfere with each other. In other words, when the adjacent surface recesses 32LH are continuous with each other, the adjacent mask holes 32H may not be spaced apart from each other. In such a case, the strength of the metal mask 32 for vapor deposition is lower than that of the metal mask 32 for vapor deposition formed using the metal mask substrate 32S for vapor deposition having the same thickness, in which the adjacent mask holes 32H are spaced apart from each other.

[0051] The metal mask substrate 32S provided in the metal mask 32 for vapor deposition shown in FIG. 3 satisfies the following [Condition 4]. [Condition 4] A halogen-based compound is not located on the back surface 32b and the inner wall surface defining the back surface recess 32SH.

[0052] In the metal mask 32 for vapor deposition shown in FIG. 3, the antifouling layer 32AF is located on the surface 32a and the inner wall surface defining the surface recess 32LH, but is not located on the back surface 32b and the inner wall surface defining the back surface recess 32SH. Therefore, a halogen-based compound is not located on the back surface 32b and the inner wall surface defining the back surface recess 32SH.

[0053] [Bonding structure of the metal mask for vapor deposition] With reference to FIG. 4, the cross-sectional structure of the bonding structure between the metal mask 32 for vapor deposition and the mask frame 31 will be described. In FIG. 4, for the sake of illustration, the illustration of the antifouling layer 32AF provided in the metal mask 32 for vapor deposition is omitted.

[0054] As shown in FIG. 4, in the metal mask substrate 32S, the portion including the edge in the metal mask substrate 32S is the outer peripheral edge portion 32E. In the outer peripheral edge portion 32E of the metal mask substrate 32S, the region where the mask holes 32H are not formed is continuous along the edge of the metal mask substrate 32S. The portion included in the outer peripheral edge portion 32E in the surface 32a is bonded to the mask frame 31.

[0055] The mask frame 31 includes an inner edge portion 31E, a frame back surface 31b, and a frame front surface 31a. The inner edge portion 31E demarcates a mask frame hole 33. The frame back surface 31b faces the vapor deposition metal mask substrate 32S. The frame front surface 31a is the surface on the side opposite to the frame back surface 31b. The inner edge portion 31E includes a part of the frame back surface 31b and a part of the frame front surface 31a. The thickness T31 of the mask frame 31, that is, the distance between the frame back surface 31b and the frame front surface 31a, is larger than the thickness T32 of the vapor deposition metal mask substrate 32S. Thereby, the mask frame 31 has higher rigidity than the vapor deposition metal mask substrate 32S. In particular, the mask frame 31 has high rigidity against the inner edge portion 31E sagging due to the self-weight of the mask frame 31 or the inner edge portion 31E being displaced toward the vapor deposition metal mask 32.

[0056] The material for forming the mask frame 31 is preferably an iron-nickel alloy or an iron-nickel-cobalt alloy. More preferably, the material for forming the mask frame 31 is the same as the alloy used as the main component of the vapor deposition metal mask substrate 32S among the iron-nickel alloy or the iron-nickel-cobalt alloy. That is, the material for forming the mask frame 31 is preferably Invar or Super Invar. When the thickness T32 of the vapor deposition metal mask 32 is thinner than 20 μm, the thickness T31 of the mask frame 31 is preferably more than twice the thickness T32 of the vapor deposition metal mask substrate 32S.

[0057] In the portion of the inner edge 31E included in the back surface 31b of the frame, there is a joint portion 31BN where the front surface 32a and the back surface 31b of the mask frame 31 are joined. The joint portion 31BN is located continuously or intermittently over substantially the entire circumference of the inner edge 31E. The joint portion 31BN may be a weld mark formed by welding the back surface 31b and the front surface 32a. Alternatively, the joint portion 31BN may be a joint layer that joins the back surface 31b and the front surface 32a, and may be a layer separate from both the mask frame 31 and the vapor deposition metal mask 32.

[0058] Note that when the mask frame 31 is joined to the main frame 20, a stress that pulls outwardly of the mask frame 31 is applied by the main frame 20. At this time, the mask frame 31 is joined to the main frame 20 such that each end portion in the direction in which the mask frame 31 extends protrudes outwardly of the main frame 20.

[0059] [Number of vapor deposition metal masks] With reference to FIGS. 5A and 5B, the relationship between the number of mask frame holes 33 provided in the vapor deposition metal mask sheet 30 and the number of vapor deposition metal masks 32 will be described. Note that in FIGS. 5A and 5B, for the sake of illustration, the illustration of the antifouling layer 32AF is omitted.

[0060] As shown in FIG. 5A, the mask frame 31 has, as a plurality of mask frame holes 33, for example, three mask frame holes 33A, 33B, and 33C. As shown in FIG. 5B, the vapor deposition metal mask sheet 30 includes one vapor deposition metal mask 32 corresponding to each of the mask frame holes 33A, 33B, and 33C. More specifically, the inner edge 31E partitioning the first mask frame hole 33A is joined to the first vapor deposition metal mask 32A. The inner edge 31E partitioning the second mask frame hole 33B is joined to the second vapor deposition metal mask 32B. The inner edge 31E partitioning the third mask frame hole 33C is joined to the third vapor deposition metal mask 32C.

[0061] Since the evaporation metal mask sheet 30 is repeatedly used for a plurality of evaporation targets, high precision is required for each of the plurality of mask holes 32H provided in the evaporation metal mask sheet 30 in terms of position, structure, etc. Thus, when the number of mask frame holes 33A, 33B, 33C required for one mask frame 31 is borne by three evaporation metal masks 32, it has the following advantages. That is, when the evaporation metal mask sheet 30 includes one evaporation metal mask 32 that covers all the mask frame holes 33A, 33B, 33C, or when the evaporation metal mask sheet 30 is constituted only by the evaporation metal mask 32, that is, when the mask frame 31 and the evaporation metal mask 32 are integrated, it has the following advantages. That is, when deformation occurs in a part of one evaporation metal mask 32, it is possible to reduce the size of the new evaporation metal mask 32 to be exchanged with the evaporation metal mask 32 before exchange. Also, it is possible to suppress the consumption amount of various materials required for the manufacture and repair of the evaporation metal mask sheet 30.

[0062] Note that the inspection regarding the structure of the mask hole 32H is preferably performed in a state where the evaporation metal mask 32 is joined to the mask frame 31. Therefore, the joint portion 31BN is preferably configured such that the deformed evaporation metal mask 32 can be exchanged for a new evaporation metal mask 32. Thereby, it is possible to use one mask frame 31 for a plurality of evaporation metal mask substrates 32S, and to perform inspections on different evaporation metal masks 32 using one mask frame 31. And, the thinner the thickness of the evaporation metal mask substrate 32S constituting the evaporation metal mask 32, and the smaller the size of the mask hole 32H, the more likely the yield of the evaporation metal mask 32 is to decrease. Therefore, the configuration in which one evaporation metal mask 32 is provided for each of the plurality of mask frame holes 33 is preferable for the evaporation metal mask sheet 30 that requires high definition.

[0063] In the mask frame 31, a plurality of mask frame holes 33 form a mask hole row. The mask frame 31 is not limited to a configuration having one mask hole row, and may have a configuration having a plurality of mask hole rows. Thus, the metal mask sheet 30 for vapor deposition may have a configuration in which a plurality of columns composed of a plurality of metal masks 32 for vapor deposition are arranged side by side.

[0064] [Method for manufacturing a metal mask for vapor deposition] With reference to FIGS. 6 to 8, a method for manufacturing the metal mask 32 for vapor deposition will be described. Note that the method for manufacturing the metal mask 32 for vapor deposition described with reference to FIG. 2 and the method for manufacturing the metal mask 32 for vapor deposition described with reference to FIG. 3 are different in the step of performing wet etching on the metal mask substrate 32S for vapor deposition, while the other steps are substantially the same. That is, the metal mask 32 for vapor deposition described with reference to FIG. 2 is manufactured by a single-sided etching method in which processing is performed only from one side, i.e., one side of the metal mask substrate 32S for vapor deposition. The metal mask 32 for vapor deposition described with reference to FIG. 3 is manufactured by a double-sided etching method in which the metal mask substrate 32S for vapor deposition is processed from both sides.

[0065] Since it is possible to control the size of the front surface opening H1 and the size of the back surface opening H2, it is preferable to use the double-sided etching method for manufacturing the metal mask 32 for vapor deposition. On the other hand, when the thickness of the metal mask substrate 32S for vapor deposition is 15 μm or less, since the thickness is thin, it is possible to use the single-sided etching method without using the double-sided etching method. Hereinafter, the manufacturing method of the metal mask substrate 32S for vapor deposition described above with reference to FIG. 2 will be mainly described. In contrast, regarding the manufacturing method of the metal mask 32 for vapor deposition described above with reference to FIG. 3, the description overlapping with the manufacturing method of the metal mask 32 for vapor deposition shown in FIG. 2 will be omitted. Here, as an example in the manufacturing method of the metal mask 32 for vapor deposition, the manufacturing method when using Invar as the material for forming the metal mask substrate 32S for vapor deposition is shown.

[0066] As shown in Fig. 6, the method for manufacturing the metal mask 32 for vapor deposition first prepares the metal mask substrate 32S for vapor deposition by means of the above-described rolling and polishing (see Fig. 6A). At this time, in order to make the thickness of the metal mask substrate 32S for vapor deposition the desired thickness, a relatively thick inverse sheet is prepared, and then the inverse sheet is thinned by etching. Thereby, a metal mask substrate 32S for vapor deposition having the desired thickness can be obtained. When the thickness of the metal mask substrate 32S for vapor deposition is 15 μm or less, particularly 10 μm or less, since it is difficult to handle the metal mask substrate 32S for vapor deposition, before thinning the thickness of the inverse sheet, the inverse sheet is bonded to the glass substrate 42 via the resin layer 41 which is a support layer. The resin layer 41 is preferably formed from polyimide. When thinning the thickness of the inverse sheet, the entire surface of the inverse sheet is etched with an etching solution.

[0067] Next, a resist layer PR is formed on one of the target surfaces of the metal mask substrate 32S for vapor deposition (see Fig. 6B), and then, by performing exposure and development on the resist layer PR, a resist mask RM is formed on the target surface (see Fig. 6C).

[0068] In the method for manufacturing the metal mask 32 for vapor deposition, an etching method is used in which the metal mask substrate 32S for vapor deposition is selectively dissolved with an etching solution. The etching method may be either a single-sided method (see Fig. 6) in which processing is performed only from one side as described above, or a double-sided etching method (see Fig. 8) in which processing is performed from both sides. Since it is possible to control the size of the front surface opening H1 and the size of the back surface opening H2, it is preferable to use the double-sided etching method. However, when the thickness of the metal sheet is 15 μm or less, as described above, the single-sided etching method is used. When the thickness of the metal mask substrate 32S for vapor deposition is relatively thick to the extent that the double-sided etching method is used, the metal mask sheet 30 is often constituted only by the metal mask 32 for vapor deposition.

[0069] In the vapor deposition metal mask substrate 32S provided with the resist layer PR, patterning of the resist layer PR is performed using a photolithography method. The resist layer PR may be formed from a negative photosensitive resin or a positive photosensitive resin. When using a negative photosensitive resin, the portion of the resist layer PR where no opening is formed is exposed through a desired pattern mask, while when using a positive photosensitive resin, the portion of the resist layer PR where an opening is formed is exposed through a desired pattern mask. As a light source for exposing the resist layer PR, an ordinary high-pressure mercury lamp or the like may be used. Note that the resist layer PR may be a dry film resist covered with a carrier film or a resist layer formed from a coating solution.

[0070] Subsequently, when using a dry film resist, after peeling the carrier film from the dry film resist, the dry film resist is developed. An alkaline aqueous solution is used as the developer. The alkaline aqueous solution may be, for example, an aqueous sodium hydroxide solution, an aqueous sodium carbonate solution, an aqueous sodium hydrogen carbonate solution, an amine-based aqueous solution, or a mixed aqueous solution thereof, or an aqueous solution obtained by adding a suitable surfactant or the like thereto. After development of the resist layer PR, the resist mask RM obtained by development of the resist layer PR is dried using a hot air dryer and an IR (Infrared Radiation) dryer or the like.

[0071] In order to form the mask holes 32H in the vapor deposition metal mask substrate 32S positioned on the glass substrate 42 via the resin layer 41, the vapor deposition metal mask substrate 32S is etched with an acidic etching solution (see FIG. 6D). The etching of the vapor deposition metal mask substrate 32S can be carried out under known conditions. As the acidic etching solution, for example, a solution in which any one of perchloric acid, hydrochloric acid, sulfuric acid, formic acid, and acetic acid is mixed with a ferric perchlorate solution and a mixed solution of a ferric perchlorate solution and a ferric chloride solution is used. The etching method may be a dip method in which the vapor deposition metal mask substrate 32S is immersed in the acidic etching solution, a spray method in which the acidic etching solution is sprayed onto the vapor deposition metal mask substrate 32S, or a spin method in which the acidic etching solution is dropped onto the vapor deposition metal mask substrate 32S rotated by a spinner. Next, the resist mask RM is removed from the surface of the vapor deposition metal mask substrate 32S (see FIG. 6E).

[0072] With the support layer, that is, the resin layer 41 made of polyimide and the glass substrate 42 attached to the back surface 32b of the vapor deposition metal mask substrate 32S, the surface roughness of the surface 32a is adjusted with a chemical polishing solution. The chemical polishing solution for adjusting the surface roughness is an acidic solution containing an oxidizing agent. The acidic solution is generally a combination of an oxidizing agent, an acid, that is, either an inorganic acid or an organic acid, and a stabilizer. That is, the acidic solution contains an oxidizing agent, an acid, and a stabilizer.

[0073] The composition of the acidic solution is determined by the type of metal to be chemically polished. In the case of an iron-nickel alloy, as an oxidizing agent, in addition to the acidic etching solution described above, hydrogen peroxide can be used. Specifically, the oxidizing agent may be hydrogen peroxide, the acid may be sulfuric acid or hydrofluoric acid, and the stabilizer may be acetamide, benzamide, phenol, ethanol, ethylene glycol, etc. Note that the acidic solution may contain, in addition to the oxidizing agent, acid, and stabilizer, a pitting inhibitor, other inorganic acids or organic acids, etc., and an acidic solution can be prepared by diluting these materials with water. By changing at least one of the treatment temperature and treatment time with the chemical polishing solution, it is possible to adjust the surface roughness Sa on the surface 32a.

[0074] On the vapor deposition metal mask substrate 32S with the adjusted surface roughness Sa, a stain-proof layer 32AF is provided on the vapor deposition metal mask substrate 32S from the surface 32a side of the vapor deposition metal mask substrate 32S (see FIG. 6F). As described above, as the material for forming the stain-proof layer 32AF, a material that is insoluble in a solvent and has a property of easily removing the attached scum can be appropriately selected and used. For example, as the stain-proof layer 32AF of the present invention, a stain-proof material conventionally known in the fields of "antireflection film", "water-repellent sheet", etc. can be used.

[0075] Specific materials include, for example, mold release materials. The mold release material is a material that is insoluble in a solvent and can form the antifouling layer 32AF at a temperature that does not cause deformation to the metal mask substrate 32S for vapor deposition. The mold release material may be a fluorine-based compound, a silicone resin, or the like. From the viewpoint of enhancing antifouling properties and enhancing adhesion to the metal mask substrate 32S for vapor deposition, the release material is preferably a fluorine-based compound. Since the surface free energy of the silicone resin is greater than that of the fluorine-based compound, the antifouling property is inferior to that of the fluorine-based compound. In other words, since the surface free energy of the fluorine-based compound is smaller than the surface free energy of the silicone resin, the antifouling property is excellent with respect to the silicone resin. Further, when removing the vapor deposition material by ultrasonic cleaning, the silicone resin has lower adhesion to the metal, which is the metal mask substrate 32S for vapor deposition, than the fluorine-based compound, so the antifouling layer is likely to peel off from the metal mask substrate 32S for vapor deposition. In other words, since the fluorine-based compound has higher adhesion to the metal than the silicone resin, the antifouling layer is less likely to peel off from the metal mask substrate 32S for vapor deposition. The fluorine-based compound is preferably a fluorinated polyether compound.

[0076] Specific examples of the fluorinated polyether compound include 2101S and 2120 (manufactured by AGC Inc.) of the SURECO (registered trademark) AF series, the 2000 series of SIFEL (registered trademark) (manufactured by Shin-Etsu Chemical Co., Ltd.), and P56, P54, F10, S10, A10P, AD1700, MD700 (manufactured by Solvay) of the Fluorolink (registered trademark) series.

[0077] When the thickness of the antifouling layer 32AF is increased, the thickness of the apparent vapor deposition metal mask substrate 32S increases, and depending on the thickness of the antifouling layer 32AF, it may not be possible to prevent the occurrence of shadows. Therefore, it is desirable to determine the thickness of the antifouling layer 32AF in consideration of this point. Specifically, the thickness of the antifouling layer 32AF is preferably 100 nm or less. From the viewpoint of enhancing the ease of forming the antifouling layer 32AF, the thickness of the antifouling layer 32AF is preferably 20 nm or less, and more preferably 5 nm or more and 10 nm or less.

[0078] The back surface 32b of the vapor deposition metal mask substrate 32S is supported by the resin layer 41 which is a support layer. There is no particular limitation on the method for forming the antifouling layer 32AF on the vapor deposition metal mask substrate 32S. An antifouling layer 32AF coating liquid in which a material for forming the antifouling layer 32AF is dissolved or dispersed in an appropriate solvent is coated on the surface 32a of the vapor deposition metal mask substrate 32S, and then the antifouling layer 32AF can be formed by heating the coating liquid. The method for coating the coating liquid may be a conventionally known method such as spray coating, spin coating, dip coating, curtain coating, die coating, etc. When these coating methods are used, in the vapor deposition metal mask substrate 32S, the antifouling layer 32AF is also formed on the portion of the surface 32a that was not etched and on the inner wall surface defining the mask hole 32H having an inverted frustum shape. By forming the antifouling layer 32AF on the surface 32a and the inner wall surface of the mask hole 32H, even when slag adheres to the flat surface of the surface 32a and the inner wall surface of the mask hole 32H, the adhered slag can be easily removed by washing. However, it is preferable that the antifouling layer 32AF is not formed in the region around the joint portion 31BN with the mask frame 31 on the surface 32a, that is, the region including the portion forming the joint portion 31BN. Therefore, a masking layer is provided in advance before forming the antifouling layer 32AF so that the antifouling layer 32AF is not formed in the region including the portion forming the joint portion 31BN on the surface 32a.

[0079] By removing the resin layer 41 and the glass substrate 42 from the vapor deposition metal mask substrate 32S provided with the antifouling layer 32AF, a vapor deposition metal mask 32 including the vapor deposition metal mask substrate 32S and the antifouling layer 32AF can be obtained (see FIG. 6G). When the resin layer 41 and the glass substrate 42 are removed from the vapor deposition metal mask substrate 32S for a thin film, since the vapor deposition metal mask 32 is thin, it is difficult to handle the vapor deposition metal mask 32. Therefore, as shown in FIGS. 4 and 5 referred to above, and as described below with reference to FIG. 7, after joining the vapor deposition metal mask 32 to the mask frame 31, the resin layer 41 and the glass substrate 42 are peeled off from the vapor deposition metal mask 32.

[0080] As shown in FIGS. 7A to 7C, a portion included in the surface 32a within the outer peripheral edge portion 32E is joined to the inner edge portion 31E (see FIG. 7A). Then, the glass substrate 42 joined to each resin layer 41 is peeled off from the resin layer 41 (see FIG. 7B). Next, the resin layer 41 joined to the vapor deposition metal mask substrate 32S is peeled off from each vapor deposition metal mask 32 (see FIG. 7C). Thereby, the above-described vapor deposition metal mask sheet 30 is obtained. In FIG. 7, for the sake of illustration, the number of vapor deposition metal masks 32 joined to the vapor deposition metal mask sheet 30 is smaller than the number of vapor deposition metal masks 32 joined to the vapor deposition metal mask sheet 30 shown in FIG. 5A.

[0081] The process of joining a part of the evaporation metal mask 32 and a part of the mask frame 31 is a process of joining the mask frame 31 to the surface of the evaporation metal mask 32 on the side opposite to the surface in contact with the resin layer 41. As described above, the mask frame 31 is preferably made of an iron-nickel alloy or an iron-nickel-cobalt alloy, and the thickness of the mask frame 31 is preferably at least twice the thickness of the evaporation metal mask 32. In this case, the mechanical strength of the evaporation metal mask sheet 30 can be increased. Furthermore, when evaporation is performed using the evaporation metal mask sheet 30, warping of the evaporation metal mask 32 due to the difference between the thermal expansion coefficient of the mask frame 31 and the thermal expansion coefficient of the evaporation metal mask 32 can be suppressed. As a result, a decrease in the accuracy of the shape of the pattern formed using the evaporation metal mask sheet 30 can be suppressed.

[0082] As described above, in the evaporation metal mask sheet 30 having the evaporation metal mask 32, when the thickness of the evaporation metal mask 32 is 3 μm or more and 15 μm or less, the thickness of the mask frame 31 is 15 μm or more and 200 μm or less, and it is preferable that the thickness of the mask frame 31 is at least twice the thickness of the evaporation metal mask 32. In the evaporation metal mask sheet 30 having the evaporation metal mask 32 capable of manufacturing a high-resolution display device, when the thickness of the evaporation metal mask 32 is 3 μm or more and 5 μm or less, the thickness of the mask frame 31 is 50 μm or more and 200 μm or less, and it is preferable that the thickness of the mask frame 31 is at least 10 times the thickness of the evaporation metal mask 32. Since the thickness of the evaporation metal mask 32 is extremely thin, by setting the thickness of the mask frame 31 to be at least 10 times the thickness of the evaporation metal mask substrate 32S, a decrease in the mechanical strength of the entire evaporation metal mask sheet 30 can be suppressed.

[0083] In the method shown in Fig. 7A, laser welding can be used to join the outer peripheral edge 32E to the inner edge 31E. Through the glass substrate 42 and the resin layer 41, the first laser beam L1 is irradiated onto the portion of the vapor deposition metal mask 32 where the joint 31BN is located. The wavelength of the first laser beam L1 may be, for example, 355 nm, 1064 nm, or 1070 nm. Therefore, the glass substrate 42 and the resin layer 41 have permeability to the first laser beam L1. In other words, the first laser beam L1 has a wavelength that can pass through the glass substrate 42 and the resin layer 41. By intermittently irradiating the first laser beam L1 along the edge of the mask frame hole 33, an intermittent joint 31BN is formed. On the other hand, by continuously irradiating the first laser beam L1 along the edge of the mask frame hole 33, a continuous joint 31BN is formed. Note that the glass substrate 42 may have a through hole for the first laser beam L1 to pass through at the site where the first laser beam L1 is irradiated. In this case, it is possible to reduce the power of the first laser beam L1 compared to the case where the glass substrate 42 does not have a through hole.

[0084] As a result, the outer peripheral edge 32E of the vapor deposition metal mask 32 and the inner edge 31E of the mask frame 31 are welded. Note that when the resin layer 41 made of polyimide and the glass substrate 42 support the vapor deposition metal mask 32 with a stress applied to the vapor deposition metal mask 32 toward the outside, it is also possible to omit the application of stress to the vapor deposition metal mask 32 in the welding of the vapor deposition metal mask 32 and the mask frame 31.

[0085] As shown in FIGS. 7B and 7C, the method for manufacturing the vapor deposition metal mask sheet 30 includes a peeling step. The peeling step is a step of peeling the resin layer 41 and the glass substrate 42 from the vapor deposition metal mask 32. The vapor deposition metal mask 32 including a plurality of mask holes 32H is supported by the resin layer 41 and the glass substrate 42 in the process of manufacturing the vapor deposition metal mask sheet 30, and in the vapor deposition metal mask sheet 30, it is supported by the mask frame 31. Therefore, the thickness of the vapor deposition metal mask substrate 32S can be made thinner than the case where the vapor deposition metal mask sheet 30 is constituted only by the vapor deposition metal mask 32. Therefore, by shortening the distance between one surface opening H1 and the other back surface opening H2 in the mask hole 32H, the structural accuracy in the pattern formed using the vapor deposition metal mask sheet 30 can be improved, and the handleability of the vapor deposition metal mask sheet 30 can be improved by the rigidity of the mask frame 31.

[0086] The peeling step includes a first peeling step (see FIG. 7B) and a second peeling step (see FIG. 7C). The first peeling step is to irradiate the interface between the resin layer 41 and the glass substrate 42 with a second laser beam L2 having a wavelength that is transmitted through the glass substrate 42 and absorbed by the resin layer 41, thereby peeling the glass substrate 42 from the resin layer 41. The wavelength of the second laser beam L2 is preferably 308 nm or more and 355 nm or less.

[0087] In the first peeling step, by irradiating the interface between the resin layer 41 and the glass substrate 42 with the second laser beam L2, the thermal energy of the second laser beam L2 is absorbed by the resin layer 41. As a result, the resin layer 41 is heated, and the strength of the chemical bond between the resin layer 41 and the glass substrate 42 is reduced. Then, the glass substrate 42 is peeled from the resin layer 41. In the first peeling step, it is preferable to irradiate the entire joint portion 31BN with the second laser beam L2, but if it is possible to reduce the strength of the bond between the glass substrate 42 and the resin layer 41 throughout the joint portion 31BN, a part of the joint portion 31BN may be irradiated with the second laser beam L2.

[0088] At the wavelength of the second laser beam L2, it is preferable that the transmittance of the glass substrate 42 is higher than that of the resin layer 41. Thereby, compared with the case where the transmittance of the resin layer 41 is higher than that of the glass substrate 42, the efficiency of heating the portion forming the interface between the glass substrate 42 and the resin layer 41 in the resin layer 41 can be increased.

[0089] When the wavelength of the second laser beam L2 is, for example, 308 nm or more and 355 nm or less, at this wavelength, it is preferable that the transmittance of the glass substrate 42 is 54% or more and the transmittance of the resin layer 41 is 1% or less. Thereby, more than half of the light quantity of the second laser beam L2 irradiated on the glass substrate 42 passes through the glass substrate 42, and most of the second laser beam L2 passing through the glass substrate 42 is absorbed by the resin layer 41. Therefore, the efficiency of heating the portion forming the interface between the glass substrate 42 and the resin layer 41 in the resin layer 41 can be further increased.

[0090] As described above, the resin layer 41 is preferably formed of a colored polyimide among polyimides. Also, the glass substrate 42 is preferably transparent. As the material for forming the glass substrate 42, quartz glass, non-alkali glass, soda-lime glass, crystallized glass, borosilicate glass, high-silica glass, and porous glass can be used.

[0091] After the first peeling step, in the second peeling step, the resin layer 41, the vapor deposition metal mask 32, and the mask frame 31 are exposed to the chemical solution LM, and thereby the resin layer 41 is dissolved using the chemical solution LM to peel the resin layer 41 from the vapor deposition metal mask substrate 32S. As a result, the resin layer 41 is chemically removed from the vapor deposition metal mask substrate 32S. As the chemical solution LM, a liquid that can dissolve the material for forming the resin layer 41 and that has no reactivity with the material for forming the vapor deposition metal mask 32 can be used. As the chemical solution LM, for example, an alkaline solution can be used. Examples of the alkaline solution include an aqueous sodium hydroxide solution. In FIG. 7C, the dipping method is illustrated as a method of bringing the resin layer 41 into contact with the chemical solution LM, but as the method of bringing the resin layer 41 into contact with the chemical solution LM, it is also possible to use a spray type and a spin type.

[0092] Thus, in the step of peeling the resin layer 41 and the glass substrate 42 from the vapor deposition metal mask substrate 32S, the glass substrate 42 is peeled from the resin layer 41 by the first peeling step, and the resin layer 41 is peeled from the vapor deposition metal mask substrate 32S by the second peeling step. Therefore, compared with the case where the glass substrate 42 and the resin layer 41 are peeled from the vapor deposition metal mask substrate 32S due to interfacial fracture caused by an external force applied to the laminate of the glass substrate 42, the resin layer 41, and the vapor deposition metal mask 32, the external force acting on the vapor deposition metal mask 32 can be reduced. As a result, it is possible to suppress deformation of the vapor deposition metal mask 32 due to peeling of the resin layer 41 and the glass substrate 42, and thus deformation of the mask holes 32H of the vapor deposition metal mask 32.

[0093] Note that the material for forming the resin layer 41 is not limited to polyimide, and may be, for example, an ultraviolet (UV) curable adhesive. In this case, when peeling the resin layer 41 and the glass substrate 42 from the vapor deposition metal mask substrate 32S, the resin layer 41 can be cured by exposing the resin layer 41 to UV, thereby reducing the adhesiveness of the resin layer 41 to the vapor deposition metal mask substrate 32S. Subsequently, by peeling the resin layer 41 from the vapor deposition metal mask substrate 32S, it is also possible to simultaneously remove the resin layer 41 and the glass substrate 42 from the vapor deposition metal mask substrate 32S.

[0094] Note that for forming the resin layer 41 with an adhesive, for example, a UV curable easily peelable adhesive film is used. By attaching one surface of the UV curable easily peelable adhesive film to the vapor deposition metal mask substrate 32S and attaching the other surface of the UV curable easily peelable adhesive film to the glass substrate 42, the resin layer 41 located between the glass substrate 42 and the vapor deposition metal mask substrate 32S can be formed.

[0095] On the other hand, when the thickness of the vapor deposition metal mask substrate 32S is made thicker than 15 μm, especially when it is made thicker than 20 μm, as a manufacturing method of the vapor deposition metal mask 32, the double-sided etching method shown in FIG. 8 is used. In the double-sided etching method, in order to adjust the sizes of the back surface opening H2 and the front surface opening H1 of the vapor deposition metal mask substrate 32S, it is necessary to change the respective etching amounts, that is, the back surface opening H2 and the front surface opening H1 need to be formed by separate etching steps.

[0096] After acid-treating the front surface 32a and the back surface 32b of the evaporation metal mask substrate 32S using hydrochloric acid, sulfuric acid, etc., a resist layer PR for pattern formation is formed (see Fig. 8A). Specifically, a resist layer PRa is formed on the front surface 32a, and a resist layer PRb is formed on the back surface 32b. The resist material may be a negative photosensitive resin in which the portion subjected to UV exposure hardens, or a positive photosensitive resin in which the portion subjected to UV exposure dissolves in the developer. Also, the method of forming the resist layer PR may be a method of laminating a dry film resist on the evaporation metal mask substrate 32S while applying heat to the dry film resist. Alternatively, the method of forming the resist layer PR may be a method of forming a coating film by coating a liquid resist material on a metal plate by gravure coating, screen coating, etc., and then removing the solvent from the coating film using a hot air dryer or the like.

[0097] In the evaporation metal mask substrate 32S on which the resist layers PRa and PRb are formed, patterning of the resist layers PRa and PRb is performed using a photolithography method (see Fig. 8B). The resist layers PRa and PRb may be formed from a negative photosensitive resin or a positive photosensitive resin. When using a negative photosensitive resin, the portions of the resist layers PRa and PRb that do not form openings are exposed through a desired pattern mask. On the other hand, when using a positive photosensitive resin, the portions of the resist layers PRa and PRb that form openings are exposed. As the light source for exposing the resist layers PRa and PRb, an ordinary high-pressure mercury lamp or the like may be used.

[0098] Subsequently, when using a dry film resist, after peeling the carrier film from the dry film resist, the dry film resist is developed to form resist masks RMa and RMb. An alkaline aqueous solution is used as the developer. The alkaline aqueous solution may be, for example, an aqueous sodium hydroxide solution, an aqueous sodium carbonate solution, an aqueous sodium hydrogen carbonate solution, an amine-based aqueous solution, or a mixed aqueous solution thereof, or an aqueous solution with a suitable surfactant added thereto. After developing the resist layers PRa and PRb, the resist layers PRa and PRb are dried using a hot air dryer and an IR (Infrared Radiation) dryer, etc.

[0099] When etching one of the back surface 32b and the front surface 32a, a resin layer 43a, which is a protective layer, is formed so that the other surface is not etched (see FIG. 8C). For forming the resin layer 43a, an adhesive film and a liquid photosensitive resin, or polyimide, etc. are used. In the case of the double-sided etching method, generally, in order to form a back surface opening H2 having a relatively small diameter, the metal mask substrate 32S for vapor deposition is etched from the back surface 32b. That is, the back surface opening H2 is formed on the metal mask substrate 32S for vapor deposition prior to the surface opening H1 of the metal mask substrate 32S for vapor deposition. In this case, the resin layer 43a, which is the protective layer of the front surface 32a, is preferably an adhesive film. Thereby, the resin layer 43a can be formed on the resist mask RMa and peeled from the resist mask RMa, and the resin layer 43a can also serve as a support when transporting the metal mask substrate 32S for vapor deposition.

[0100] After forming the resin layer 43a on the front surface 32a, etching is performed using an acidic etching solution to form the back surface opening H2 of the back surface 32b on the metal mask substrate 32S for vapor deposition (see FIG. 8D). The etching conditions are the same as those described above in the single-sided etching method.

[0101] In order to form the resin layer 43b, which is the protective layer of the back surface 32b, the resist mask RMb is peeled off from the vapor deposition metal mask substrate 32S in which the back surface opening H2 is formed (see Fig. 8E). The peeling may be carried out under known conditions. For example, an alkaline stripping solution is used for peeling the resist mask RMb. The alkaline stripping solution may be, for example, an aqueous sodium hydroxide solution, an aqueous sodium carbonate solution, an aqueous sodium hydrogen carbonate solution, an amine-based aqueous solution, or a mixed aqueous solution thereof, or an aqueous solution obtained by adding a suitable surfactant or the like thereto.

[0102] In order to prevent the back surface 32b from being etched during the etching of the front surface 32a, the resin layer 43b, which is the protective layer of the back surface 32b, is formed by a coating method or a printing method (see Fig. 8F). For forming the resin layer 43b, a photosensitive resin which is a liquid varnish is used. The thickness of the resin layer 43b is preferably 5 μm or more and 20 μm or less. At this time, the varnish fills the back surface recess 32SH formed in the vapor deposition metal mask substrate 32S, and thereby the resin layer 43b is formed so that the back surface recess 32SH is filled with the varnish. Note that the resin layer 43b may be formed from polyimide. When the resin layer 43b is formed from polyimide, it is preferable that the resin layer 43b is formed by applying a polyimide solution, a polyamic acid solution, or the like by a coating method or a printing method to form a film, and then curing the film by heat treatment or the like.

[0103] After peeling the resin layer 43a, the front surface 32a is etched in order to form the front surface opening H1 and connect the front surface opening H1 to the back surface opening H2 (see Figs. 8G and 8H). The etching of the front surface 32a can be carried out using the same etching solution as that for the etching of the back surface 32b.

[0104] After peeling the resist mask RMa from the vapor deposition metal mask substrate 32S having the front surface opening H1 and the back surface opening H2, the antifouling layer 32AF is provided under the conditions described above by a single-sided etching method (see FIGS. 8I and 8J). When forming the antifouling layer 32AF on the vapor deposition metal mask substrate 32S, a resin layer 43b is formed on the back surface of the vapor deposition metal mask substrate 32S, and the back surface recess 32SH is filled with the resin layer 43b. Therefore, when the antifouling layer 32AF is formed so as to cover the front surface 32a of the vapor deposition metal mask substrate 32S, the antifouling layer 32AF is formed so as to cover the front surface 32a of the vapor deposition metal mask substrate 32S and the inner wall surface of the front surface recess 32LH. On the other hand, the antifouling layer 32AF is not formed on the back surface 32b of the vapor deposition metal mask substrate 32S and the inner wall surface of the back surface recess 32SH. Therefore, no halogen-based compound is located on the back surface 32b and the inner wall surface of the back surface recess 32SH.

[0105] According to the vapor deposition metal mask 32 obtained by the double-sided etching method, the vapor deposition metal mask sheet 30 may be constituted only by the vapor deposition metal mask 32 by peeling the resin layer 43b from the back surface 32b of the vapor deposition metal mask substrate 32S (see FIG. 8K). When peeling the resin layer 43b formed from a photosensitive resin or a polyimide from the vapor deposition metal mask substrate 32S, an alkaline solution can be used. Thereby, the resin layer 43b is chemically removed from the vapor deposition metal mask substrate 32S. Examples of the alkaline solution include an aqueous sodium hydroxide solution.

[0106] Alternatively, in the same manner as the operation in the single-sided etching method, after bonding the vapor deposition metal mask 32 to the mask frame 31, the vapor deposition metal mask sheet 30 may be constituted by peeling the resin layer 43b from the back surface 32b.

[0107] In addition, when the metal mask sheet 30 for vapor deposition includes the mask frame 31, an antifouling layer may be provided on the frame surface 31a of the mask frame 31 facing the vapor deposition source and on the side surface of the mask frame hole 33. Even when the mask frame 31 includes an antifouling layer, it is preferable that the antifouling layer is not located on the frame back surface 31b of the mask frame 31. That is, it is preferable that a halogen-based compound is not located on the frame back surface 31b of the mask frame 31.

[0108] In the method for manufacturing a display device using the above-described metal mask sheet 30 for vapor deposition, first, the mask device 10 equipped with the metal mask sheet 30 for vapor deposition is installed in the vacuum chamber of the vapor deposition apparatus. At this time, the mask device 10 is installed in the vacuum chamber such that the vapor deposition target such as a glass substrate faces the back surface 32b of the metal mask base material 32S for vapor deposition, and the vapor deposition source faces the antifouling layer 32AF. Then, the vapor deposition target is carried into the vacuum chamber, and the vapor deposition material is sublimated by the vapor deposition source. As a result, in the metal mask 32 for vapor deposition formed only by etching the metal mask base material 32S for vapor deposition from one side, a pattern having a shape following the back surface opening H2 is formed on the vapor deposition target facing the back surface opening H2. On the other hand, in the metal mask 32 for vapor deposition formed by etching from both the front surface 32a and the back surface 32b of the metal mask base material 32S for vapor deposition, a pattern having a shape following the portion where the front surface recess 32LH is connected to the back surface recess 32SH is formed on the vapor deposition target facing the back surface opening H2. The vapor deposition substance may be, for example, an organic light-emitting material constituting a pixel of the display device and a material for forming a pixel electrode constituting a pixel circuit of the display device.

[0109] [Example] Hereinafter, examples and comparative examples will be described with reference to Table 1. [Example 1] A rolled invar sheet was prepared, which had a square shape with sides of 110 mm, i.e., 110 mm × 110 mm square, and had a thickness of 100 μm. A glass substrate 42 was chemically bonded to the back surface of the metal sheet via a polyimide film (Kapton EN, manufactured by DuPont, 5 μm thick), thereby forming a support layer on the back surface of the metal sheet. The polyimide film is an example of the resin layer 41 that serves as the support layer.

[0110] Next, the surface of the metal sheet was degreased using a 30% aqueous sodium hydroxide solution as a degreasing agent, and then the surface of the metal sheet was acid-treated using 10% hydrochloric acid. An aqueous solution prepared by adding 4.21 mass% of acidic ammonium fluoride to 26 mass% of hydrogen peroxide solution was prepared as a chemical polishing liquid stock solution. The chemical polishing liquid was prepared by diluting the chemical polishing liquid stock solution two-fold with pure water. The surface of the metal sheet was immersed in the chemical polishing liquid heated to 50 °C for 15 minutes, thereby adjusting the thickness of the metal sheet to 10.2 μm and adjusting the surface roughness Sa on the surface of the metal sheet to 10.1 nm. Thus, a metal mask substrate 32S for vapor deposition was obtained.

[0111] A negative dry film resist was laminated on the surface 32a of the metal mask substrate 32S for vapor deposition to form a resist layer PR. In the metal mask substrate 32S for vapor deposition, the pattern portion for forming the mask holes 32H was set as a region having a size of 99 mm × 99 mm in the center of the metal mask substrate 32S for vapor deposition. That is, a pattern portion having a square shape with sides of 99 mm was set in the metal mask substrate 32S for vapor deposition such that the center of the metal mask substrate 32S for vapor deposition and the center of the pattern portion coincided. Note that, when including the peripheral portion, a region having a square shape with sides of 100 mm, i.e., 100 mm × 100 mm, was set as the metal mask substrate 32S for vapor deposition. The peripheral portion had a rectangular frame shape surrounding the pattern portion, and the width of the peripheral portion was set to 1 mm.

[0112] Using an exposure mask in which light-shielding portions having a circular shape with a diameter of 50 μm, i.e., Hole50μm / Rib50μm, are arranged in a grid pattern with a pitch of 100 μm, the resist layer PR was exposed, and then the resist layer PR was developed using a 1% aqueous sodium carbonate solution. After washing the metal mask substrate 32S for vapor deposition provided with the resist layer PR with water, the metal mask substrate 32S for vapor deposition was heated and dried at 100°C. The patterned resist layer PR thus produced, i.e., the metal mask substrate 32S for vapor deposition having the resist mask RM, was etched by a spray method using a 48% aqueous ferric chloride solution as an etching solution. Thereby, a surface opening H1 and a back surface opening H2 were formed in the metal mask substrate 32S for vapor deposition. Further, the resist mask RM was peeled off from the metal mask substrate 32S for vapor deposition with a 10% aqueous sodium hydroxide solution as a resist stripping solution. Then, after washing the metal mask substrate 32S for vapor deposition with water, the metal mask substrate 32S for vapor deposition was dried.

[0113] A coating film was formed by applying an aqueous solution of SUREC02120 (manufactured by AGC Inc.) diluted to 0.1% to the metal mask substrate 32S for vapor deposition using a two-fluid spray device, and then the metal mask substrate 32S for vapor deposition provided with the coating film was heated at 120°C for 10 minutes. Thereby, an antifouling layer 32AF was formed on the surface 32a and the inner wall surface of the mask hole 32H of the metal mask substrate 32S for vapor deposition.

[0114] Next, a mask frame 31 made of a rolled invar material was prepared. The mask frame 31 had a length of 400 mm in the longitudinal direction, a length of 50 mm in the width direction, and three mask frame holes 33. Using an infrared laser having a wavelength of 1064 nm, the metal mask substrate 32S for vapor deposition was joined to the mask frame 31 such that one metal mask substrate 32S for vapor deposition covered one mask frame hole 33. Then, after lifting off the glass substrate 42 using an ultraviolet laser having a wavelength of 308 nm, i.e., after peeling the glass substrate 42 from the resin layer 41, the resin layer 41 was peeled off from the metal mask substrate 32S for vapor deposition using an alkaline solution. Thereby, the vapor deposition metal mask sheet 30 of Example 1 was obtained.

[0115] For dimensional measurement, i.e., measurement of surface roughness Sa, a laser microscope OLS-4000 (manufactured by Olympus Corporation) was used. For elemental analysis, a scanning electron microscope S-4800 (manufactured by Hitachi High-Technologies Corporation) was used, and elemental analysis of the front surface 32a and back surface 32b of the metal mask 32 for vapor deposition was performed by measuring in the SEM-EDX mode. At this time, the presence or absence of fluorination treatment for each surface 32a, 32b and contamination such as the adhesion of halogen-based compounds were judged based on the presence or absence of peaks of halogen atoms. The thickness of the metal mask 32 for vapor deposition was measured with a micrometer K352C (manufactured by Anritsu Corporation). Also, the contact angles on the front and back surfaces of the metal mask 32 for vapor deposition were measured by dropping pure water onto each surface and then using a CA-X type contact angle meter (manufactured by Kyowa Interface Science).

[0116] The cleaning resistance was evaluated by the following method. That is, the metal mask 32 for vapor deposition actually used for the vapor deposition of αNPD (N,N'-diphenyl-N,N'-bis(1-naphthyl)-1,1'-biphenyl-4,4'-diamine) was cleaned using an ultrasonic cleaning device (W-118 ultrasonic cleaner, manufactured by Honda Electronics Co., Ltd.). At this time, 28 kHz / 5 seconds, 45 kHz / 5 seconds, and 100 kHz / 5 seconds were set as one cycle, and the metal mask 32 for vapor deposition was subjected to a cleaning process for 1 minute. The maximum value of the output of the ultrasonic cleaning device was set to 600 W, and adjustment was made by appropriately reducing the output, that is, the metal mask 32 for vapor deposition was cleaned by setting the output to 600 W or less.

[0117] The evaluation criteria were mask strength and organic matter removal. Regarding the mask strength, it was judged whether wrinkles occurred on the metal mask 32 for vapor deposition before and after cleaning. The case where no wrinkles occurred after cleaning was set as "〇", and the case where wrinkles occurred was set as "×". Regarding organic matter removal, the presence or absence of organic matter, that is, deposits of the vapor deposition material, was judged by visual observation under a microscope. The case where there was no organic matter was set as "〇", and the case where organic matter remained was set as "×". The evaluation results are shown in Table 1 below.

[0118]

Table 1

[0119] [Example 2-7] As shown in Table 1, in the metal sheet of Example 1, the thickness of the metal sheet was changed, and the surface roughness Sa was adjusted by the concentration of the chemical polishing solution and the treatment temperature, that is, the temperature of the chemical polishing solution. Other than that, the same operations as in Example 1 were performed to obtain the metal mask sheet 30 for vapor deposition of Examples 2-7. The results of evaluating the metal mask sheet 30 for vapor deposition are shown in Table 1 in the same manner as in Example 1.

[0120] [Example 8] A metal sheet made of rolled invar, having a square shape with 110 mm × 110 mm square, that is, a side length of 110 mm, and a thickness of 100 μm was prepared. After degreasing the surface of the metal sheet using a 30% aqueous sodium hydroxide solution as a degreasing solution, the surface of the metal sheet was acid-treated using 10% hydrochloric acid. At this time, the same chemical polishing solution as in Example 1 was prepared, and the surface of the metal sheet was acid-treated under the same conditions as in Example 1. As a result, the thickness of the metal sheet was adjusted to 99.6 mm, and the surface roughness Sa on the surface of the metal sheet was adjusted to 10.5 nm. Thus, the metal mask substrate 32S for vapor deposition was obtained.

[0121] A negative dry film resist was laminated on both sides of the metal mask substrate 32S for vapor deposition to form a resist layer PR. On the back surface 32b of the metal mask substrate 32S for vapor deposition, among the mask holes 32H, the back surface pattern portion forming the back surface opening H2 was set as a region having a size of 99 mm × 99 mm in the center of the back surface 32b. That is, a back surface pattern portion having a square shape with a side length of 99 mm was set on the metal mask substrate 32S for vapor deposition so that the center of the back surface and the center of the back surface pattern portion were coincident. The resist layer PRb was exposed using an exposure mask in which light-shielding portions having a circular shape with a diameter of 30 μm were arranged in a lattice pattern at a pitch of 100 μm.

[0122] Also, in the metal mask substrate 32S for vapor deposition, among the mask holes 32H, the surface pattern portion that forms the surface opening H1 was set as a region having a size of 99 mm × 99 mm at the center of the surface 32a. That is, a surface pattern portion having a square shape with a side length of 99 mm was set on the vapor deposition metal mask substrate 32S so that the center of the surface 32a and the center of the surface pattern portion coincide. Then, a resist layer PRa was exposed using an exposure mask in which light-shielding portions having a circular shape with a diameter of 50 μm are arranged in a lattice pattern at a pitch of 100 μm. In the exposure mask for exposing the resist layer PRb located on the back surface 32b, the positions of the two exposure masks were aligned so that the centers of the respective openings faced the centers of the openings formed in the exposure mask for exposing the resist layer PRa located on the surface 32a. Then, the resist layers PRa and PRb were developed with a 1% aqueous sodium carbonate solution, thereby forming resist masks RMb and RMa.

[0123] After washing with water the vapor deposition metal mask substrate 32S provided with the resist masks RMa and RMb, the vapor deposition metal mask substrate 32S was heated and dried at 100°C. Next, a resin layer 43a made of an adhesive film as a protective layer was provided on the resist mask RMa located on the surface 32a of the vapor deposition metal mask substrate 32S. The vapor deposition metal mask substrate 32S having the resist mask RMb located on the back surface 32b was etched by a spray method using a 48% aqueous ferric chloride solution as an etching solution. Thereby, a back surface opening H2 and a back surface recess 32SH were formed in the vapor deposition metal mask substrate 32S.

[0124] Furthermore, the resist mask RMb was peeled off from the vapor deposition metal mask substrate 32S with a 10% aqueous sodium hydroxide solution as a resist stripping solution. Then, after washing the vapor deposition metal mask substrate 32S with water, the vapor deposition metal mask substrate 32S was dried.

[0125] A protective varnish made of a photosensitive resin was applied onto the back surface 32b of the etched metal mask substrate 32S for vapor deposition by means of a bar coater, and then the protective varnish was dried and cured, thereby providing a resin layer 43b which is a protective layer. Next, the resin layer 43a located on the front surface 32a of the metal mask substrate 32S for vapor deposition was peeled off, and the front surface 32a of the metal mask substrate 32S for vapor deposition was etched using an etching solution similar to that for etching the back surface. Thereby, a surface opening H1 and a surface recess 32LH were formed on the metal mask substrate 32S for vapor deposition.

[0126] Furthermore, the resist mask RMa was peeled off from the metal mask substrate 32S for vapor deposition using a 10% aqueous sodium hydroxide solution which is a resist stripping solution. Then, after the metal mask substrate 32S for vapor deposition was washed with water, the metal mask substrate 32S for vapor deposition was dried. With the resin layer 43b attached to the back surface 32b of the metal mask substrate 32S for vapor deposition, by performing the same operations as in Example 1, an antifouling layer 32AF was formed on the front surface 32a of the metal mask substrate 32S for vapor deposition and on the inner wall surface defining the surface recess 32LH. Thereafter, the resin layer 43b was peeled off from the metal mask substrate 32S for vapor deposition, thereby obtaining the metal mask sheet 30 for vapor deposition of Example 8.

[0127] [Comparative Example 1] In Example 6, by performing the same operations as in Example 6 except that the antifouling layer 32AF was not provided, the metal mask sheet 30 for vapor deposition of Comparative Example 1 was obtained. Since the antifouling layer 32AF was not provided on the metal mask sheet 30 for vapor deposition of Comparative Example 1, even when ultrasonic cleaning was performed on the metal mask sheet 30 for vapor deposition, the deposits of the vapor deposition material could not be removed. Furthermore, when the output of the ultrasonic cleaning was increased to remove the deposits of the vapor deposition material, wrinkles occurred on the metal mask sheet 30 for vapor deposition.

[0128] [Comparative Example 2] In Comparative Example 2, a metal mask sheet 30 for vapor deposition was obtained by performing the same operations as in Example 1, except that chemical polishing was not performed and the antifouling layer 32AF was not provided. In the metal mask sheet 30 for vapor deposition of Comparative Example 2, it was confirmed that the surface roughness Sa was 79.8 nm. Further, since the antifouling layer 32AF was not provided on the metal mask sheet 30 for vapor deposition, the deposits of the vapor deposition material could not be removed even by ultrasonic cleaning. Furthermore, the deposits of the vapor deposition material could not be removed unless the output of the ultrasonic cleaning was increased to 600 W, and wrinkles occurred on the metal mask sheet 30 for vapor deposition.

[0129] [Comparative Example 3] In Comparative Example 3, a metal mask sheet 30 for vapor deposition was obtained by performing the same operations as in Example 1, except that the conditions of chemical polishing were changed. In the metal mask sheet 30 for vapor deposition of Comparative Example 3, it was confirmed that the surface roughness Sa was 5.5 nm, that is, less than 10 nm. Therefore, the deposits of the vapor deposition material could be easily removed. However, the deposits deposited on the metal mask sheet 30 for vapor deposition during vapor deposition peeled off from the metal mask sheet 30 for vapor deposition, and the peeled deposits fell onto the vapor deposition source, resulting in the generation of sparks. As a result, the film surface after vapor deposition, that is, the film formed on the substrate by vapor deposition, was uneven.

[0130] [Comparative Example 4] In Comparative Example 4, a metal mask sheet 30 for vapor deposition was obtained by performing the same operations as in Example 1, except that chemical polishing was not performed. In the metal mask sheet 30 for vapor deposition of Comparative Example 4, it was confirmed that the surface roughness Sa was 98.6 nm, that is, more than 80 nm. Therefore, the deposits of the vapor deposition material could not be removed even by ultrasonic cleaning. Furthermore, the deposits of the vapor deposition material could not be removed unless the output of the ultrasonic cleaning was increased to 600 W, and wrinkles occurred on the metal mask sheet 30 for vapor deposition due to this.

[0131] [Comparative Example 5] In Example 8, before applying the antifouling layer 32AF, the resin layer 43b on the back surface 32b was peeled off, and then the antifouling layer 32AF was applied to the vapor deposition metal mask substrate 32S, thereby obtaining the vapor deposition metal mask sheet 30 of Comparative Example 5. As a result, a vapor deposition metal mask 32 having the antifouling layer 32AF on both the front surface 32a and the back surface 32b of the vapor deposition metal mask substrate 32S was obtained. As a result of performing elemental analysis on the back surface 32b of the vapor deposition metal mask 32, it was confirmed that the back surface 32b was contaminated due to the adhesion of a fluorine compound, which is a halogen-based compound. If the halogen-based compound is located on the back surface 32b of the vapor deposition metal mask 32, the vapor deposition target such as a glass substrate will be contaminated, and the halogen-based compound will cause a decrease in the luminous efficiency and lifespan of the light-emitting element. Therefore, it cannot be used as the vapor deposition metal mask 32.

[0132] Note that the material for forming the antifouling layer 32AF may be changed to a silicone resin or a hybrid material in which a fluorine-based compound is blended with the silicone resin, provided that the antifouling layer 32AF has the required antifouling property and adhesion. The silicone resin may be, for example, KR-400 (manufactured by Shin-Etsu Chemical Co., Ltd.), Modiper FS700 (manufactured by NOF Corporation), Full Shade (manufactured by Toyochem Co., Ltd.), etc. The hybrid material may be, for example, KR-400F (manufactured by Shin-Etsu Chemical Co., Ltd.), etc.

Explanation of Reference Numerals

[0133] 10... Mask device, 20... Main frame, 21... Main frame hole, 30... Vapor deposition metal mask sheet, 31... Mask frame, 31E... Inner edge portion, 31BN... Joint portion, 31a... Frame front surface, 31b... Frame back surface, 32... Vapor deposition metal mask, 32E... Outer peripheral edge portion, 32a... Front surface, 32b... Back surface, 32H... Mask hole, 32S... Vapor deposition metal mask substrate, 33... Mask frame hole, 41, 43a, 43b... Resin layer, 42... Glass substrate, H1... Front surface opening, H2... Back surface opening, PR... Resist layer, RM... Resist mask.

Claims

1. A surface having a first opening facing a vapor deposition source provided in a vapor deposition apparatus, A back surface on the side opposite to the surface, the back surface having a second opening smaller than the first opening, A through hole communicating with the first opening and the second opening, the through hole having an inverted frustum shape, a vapor deposition metal mask comprising a vapor deposition metal mask substrate provided with the through hole, Located on the inner wall surface defining the surface and the through hole, further comprising an antifouling layer containing a fluorine compound, On the back surface, a halogen-based compound containing a halogen atom is not located, The contact angle of the surface of the antifouling layer with respect to water is 90° or more, The surface roughness Sa on the surface of the vapor deposition metal mask substrate is 10 nm or more and 80 nm or less, The thickness of the antifouling layer is 20 nm or less Vapor deposition metal mask.

2. A surface having a first opening facing a vapor deposition source provided in a vapor deposition apparatus, A back surface on the side opposite to the surface, the back surface having a second opening smaller than the first opening, A through hole communicating with the first opening and the second opening, the through hole including the first opening and having an inverted frustum shape, the through hole including the second opening and having a frustum shape and being smaller than the first hole portion, a vapor deposition metal mask comprising a vapor deposition metal mask substrate provided with the through hole, The surface and an inner wall surface defining the first hole portion are provided with an antifouling layer containing a fluorine compound, On the back surface and the inner wall surface defining the second hole portion, a halogen-based compound containing a halogen atom is not located, The contact angle of the surface of the antifouling layer with respect to water is 90° or more, The surface roughness Sa on the surface of the vapor deposition metal mask substrate is 10 nm or more and 80 nm or less, The thickness of the antifouling layer is 20 nm or less Vapor deposition metal mask.

3. The material forming the vapor deposition metal mask substrate is an iron-nickel alloy or an iron-nickel-cobalt alloy The vapor deposition metal mask according to claim 1 or 2.

4. The thickness of the vapor deposition metal mask substrate is 1 μm or more and 100 μm or less The vapor deposition metal mask according to any one of claims 1 to 3.

5. A method for manufacturing a vapor deposition metal mask, Preparing a metal evaporation mask substrate made of metal, having a front surface for forming a first opening facing an evaporation source provided in an evaporation apparatus, and a back surface located on the side opposite to the front surface and for forming a second opening smaller than the first opening. Forming a resin layer on the back surface. By wet etching the evaporation metal mask substrate from the front surface, forming a through-hole having an inverted frustum shape, thereby forming the first opening on the front surface and the second opening on the back surface. Forming an antifouling layer containing a fluorine compound on the front surface and the inner wall surface defining the through-hole. After forming the antifouling layer, chemically removing the resin layer from the evaporation metal mask substrate by exposing the evaporation metal mask substrate and the resin layer to an alkaline solution. A method for manufacturing an evaporation metal mask, comprising:

6. The resin layer is made of polyimide. The method for manufacturing an evaporation metal mask according to claim 5.

7. A method for manufacturing an evaporation metal mask, comprising: Preparing a metal evaporation mask substrate made of metal, having a front surface for forming a first opening facing an evaporation source provided in an evaporation apparatus, and a back surface located on the side opposite to the front surface and for forming a second opening smaller than the first opening. Providing a second hole portion having a frustum shape with the second opening on the back surface by wet etching. Providing a resin layer on the back surface so as to cover the second opening. By wet etching the evaporation metal mask substrate from the front surface, forming a first hole portion having an inverted frustum shape and the first opening, thereby forming a through-hole by the second hole portion and the first hole portion. Forming an antifouling layer containing a fluorine compound on the front surface and the inner wall surface defining the first hole portion. After forming the antifouling layer, chemically removing the resin layer from the evaporation metal mask substrate by exposing the resin layer and the evaporation metal mask substrate to an alkaline solution. A method for manufacturing an evaporation metal mask, comprising:

8. The resin layer is made of a photosensitive resin. The method for manufacturing an evaporation metal mask according to claim 7.

9. The resin layer is made of polyimide. The method for manufacturing an evaporation metal mask according to claim 7.

10. A method for manufacturing an evaporation metal mask, comprising: Preparing a metal mask substrate for vapor deposition made of metal, comprising a front surface for forming a first opening facing a vapor deposition source provided in the vapor deposition apparatus, and a back surface located on the side opposite to the front surface for forming a second opening smaller than the first opening. Forming a resin layer on the back surface. Forming a through-hole having an inverted frustum shape by wet-etching the vapor deposition metal mask substrate from the front surface, thereby forming the first opening on the front surface and the second opening on the back surface. Forming an antifouling layer containing a fluorine compound on the front surface and the inner wall surface defining the through-hole. After forming the antifouling layer, exposing the vapor deposition metal mask substrate and the resin layer to ultraviolet rays to reduce the adhesion of the resin layer to the vapor deposition metal mask substrate, and Peeling off the resin layer with reduced adhesion from the vapor deposition metal mask substrate. A method for manufacturing a metal mask for vapor deposition, comprising:

11. The resin layer is made of an ultraviolet curable adhesive. The method for manufacturing a metal mask for vapor deposition according to claim 10.

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